document.write( "Question 191276: Says to factor by grouping?\r
\n" ); document.write( "\n" ); document.write( "40a^4-120a^2+90 \n" ); document.write( "
Algebra.Com's Answer #143562 by Edwin McCravy(20059)\"\" \"About 
You can put this solution on YOUR website!
Says to factor by grouping?
\n" ); document.write( "40a^4-120a^2+90\r
\n" ); document.write( "\n" ); document.write( "
\r\n" );
document.write( "\"40a%5E4-120a%5E2%2B90\"\r\n" );
document.write( "\r\n" );
document.write( "First factor out \"10\"\r\n" );
document.write( "\r\n" );
document.write( "\"10%284a%5E4-12a%5E2%2B9%29\"\r\n" );
document.write( "\r\n" );
document.write( "In the parentheses, multiply the first coefficient 4\r\n" );
document.write( "by the last coefficient 9, getting 36.  Write down\r\n" );
document.write( "all pairs of integer factors whose product is 36.\r\n" );
document.write( "They are\r\n" );
document.write( "\r\n" );
document.write( "1*36\r\n" );
document.write( "2*18\r\n" );
document.write( "3*12\r\n" );
document.write( "4*9\r\n" );
document.write( "6*6\r\n" );
document.write( "\r\n" );
document.write( "Since the last sign in the parentheses is +, we\r\n" );
document.write( "add those:\r\n" );
document.write( "\r\n" );
document.write( "1+36 = 37\r\n" );
document.write( "2+18 = 20\r\n" );
document.write( "3+12 = 15\r\n" );
document.write( " 4+9 = 13 \r\n" );
document.write( " 6+6 = 12\r\n" );
document.write( "\r\n" );
document.write( "Since the middle coefficient of \"%284a%5E4-12a%5E2%2B9%29\"\r\n" );
document.write( "is 12, and since 12 = 6+6 we write -12a^2 as -6a^2-6a^2\r\n" );
document.write( "\r\n" );
document.write( "\"10%284a%5E4-12a%5E2%2B9%29\"\r\n" );
document.write( "\r\n" );
document.write( "\"10%284a%5E4-6a%5E2-6a%5E2%2B9%29\"\r\n" );
document.write( "\r\n" );
document.write( "Factor the first two terms in the parentheses by factoring \r\n" );
document.write( "out \"2a%5E2\"\r\n" );
document.write( "\r\n" );
document.write( "\"10%282a%5E2%282a%5E2-3%29-6a%5E2%2B9%29\"\r\n" );
document.write( " \r\n" );
document.write( "Factor the last two terms in the parentheses by factoring \r\n" );
document.write( "out \"-3\"\r\n" );
document.write( "\r\n" );
document.write( "\"10%282a%5E2%282a%5E2-3%29-3%282a%5E2-3%29%29\"\r\n" );
document.write( "\r\n" );
document.write( "Inside the outer parentheses take out \r\n" );
document.write( "the inner parentheses \"%282a%5E2-3%29\"\r\n" );
document.write( "\r\n" );
document.write( "\"10%282a%5E2-3%29%282a%5E2-3%29\"\r\n" );
document.write( "\r\n" );
document.write( "Notice the parenthesis can be written once as squared:\r\n" );
document.write( "\r\n" );
document.write( "\"10%282a%5E2-3%29%5E2\"\r\n" );
document.write( "\r\n" );
document.write( "Edwin
\n" ); document.write( "
\n" );